Primer



May 8, 1928. I

' J. A. DICKERMAN PRIMER IlNVENTOR Original Filed Sept. 1. 1920 JOHN A DICK ERMA".

BY M

ATTORNEY WI TNESS Patented May 8, 1928.

' UNITED STATES P om JOHN A. moxnmmn, or Baroque-0R1, CONNECTICUT, 'assroivon TO REMINGTON ARMS"GOMPANY, ino 'n conroaacrron or DELAWARE.

Panama.

Application filed September}, 1920, serial N0. l07,306. aenewea February .8, was, i

A furtherobjectis to reduce puncturing,

of the primer cups by so constructing the I anvil that it may be made'o-f relatively soft material.

Other objects and advantages will appear in the following description of .a preferred form of the invention taken in connection with the attached drawing, wherein i Fig. l is an enlarged axial cross sectional view of a cartridge shell and primer made according to the present invention.

:2 is an enlarged axial cross sectional view taken at right angles to the view of Fig. 1, and a Fig. 3 is a-plan view, further enlarged, of the anvil of said primer. 3

In said views, the numeral 4 represents a cartridge shell of usual construction, formed with a primer pocket 5 and a flash hole 6. The primer which is located in said pocket preferably comprises a cup containing the detonating material 9 and having cylindrical side walls 7 and a bottom 8. i

The anvil comprises the circular top plate 13. having its entire periphery bearing within said cup. The plate may be formed with the downwardly extending flange 12 preferablv bent at right angles to increase It is slit.

its area of contact with the cup. at 14 and 15 and the intervening metal strip is bent inward, forming an anvil bridge 16 of substantially the form shown in Fig. 1 the sides of which are open to provide a flash passage to permit the flash to reach the propelling powder charge. The apex 17 ,of the anvil bridge lies against or adjacent the detonating substance and serves as a support against which the detonating substance is driven by the impact of the firing pin or striker. V

An anvil of this construction has the advantage of being very firmly held in the cup on account of the large area of its bearing its entire circu 'nferencey Where the anvil has a bearing only'part way around, it distorts the. cup and it is held surface and because it has a- .beari'ngiaround in place: merely by the force required .to. dis-.

tort thecup; In thelprimerof the resent nvention, the cup is slightly expanded-by the anvil and 1t contracts upon the anvil with an equal force at all points ofits periphery v thereby-absolutely preventing the accidental removal of the anvil.

The metal of the top plate 13 outside of the slits 1 and 15 is preferably left .iniplace forming baflle plates 18 and 19 whichserve to direct the blast of the detonation toward the axis of the primer and cartridge so that they will the more easily pass through relativelysmall flash hole 6 to ignite the ex plosivecharge. In constructing primers it.

is very essentialithat the size of the flash passage be very accurately determined for; the reason that if the passage is too small the primer may be blown out on account of the pressure of the" gases generated by the detonating material; if it istoo large the primermay be blown out by the pressure of the gases of the propelling charge. The battle plates 18 and 19 serve as -a barrier to the .direct flow of the gases, and provide a a tortuous flash passagewhich is ofsutlieient' area and the proper shape to allow. the flash to reach the propelling powder While settii'ig up suflicient wire drawing effect to preyent the gases of the propelling charge blowmg out the primer. Such an anvil possesses, great rigidity against contraction and it may therefore bemade of soft metal, as copper. Anvils as usually constructed must be made of fairly hard material, as brass in order to provide sufficientstrengtl'i and rigidity. As the cups usually consist largely of copper they are so soft thatthey will be easily punctured by the blow of the firing pin orstriker when supported by an anvil of hard metal. When a soft metal. as an alloy of more than about 85% copper is used for anvils the tendency to puncture is very greatly reduced' Onaccount of the greatrigidity against contraction possessedby the anvil of the present inventlon it may be. made of copper or other soft material, whereby the percentage of punctured primers, is reduced to a minimum. y

Having now thus described the invention, and a specific embodiment thereof, as well as the function and mode of operation of the same, what I claim as new and desire to secure ,by Letters Patent of the United States is 1. In a primer, thecolnbination-ot a cup and an anvil therein comprising a circular plate having its entire periphery bearing in said cup, a part of said plate extending inward to "form an apex against which the detonating material may bear and another part of the plate forming a bafiie.

2. In a primer, the combination of a cup and an'anvil therein comprising a circular plate having its entire periphery-bearing in said cup, at part of said plate comprising a strip near the'center thereof having been bent inward to form an apex against which the detonating material may bear.

3. An anvil for primers comprising a plate formed with spaced slits and having the material between the slits bent out to form an anvil apex and a flash passage;

4. An anvil for primers comprising a plate formed with spaced slits and having the material between the slits bent out to form an anvil apex and a flash passage, and

having its edges bent at right angles to form flanges.

5 In a primer, the combination of a cup and anvil, said anvil comprising a. circular plate formed with flanges bearing within said cup, said plate being formed with slits and the material between said slits bent inwardto form'an'a nvil apex and a flash passage. I

6. In a primer, the combination of a cup and an anvil therein comprising a circular plate having itsentire periphery bearing in said cup, a part of said plate extending inward to form an a-pexagainst which the detonating material may bear, and to term and an anvil comprising a plate, said plate comprising an inwardlybent apex and flash passage forming portion, a fiat portion forming a baflie adjacent said flash passage.

9. An anvil for primers comprising a plate formed with spaced slits having the materialbetwecn the slits bentont to form an anvil apex and a flash passage, its edges bent at right angles to form flanges and 'baflie portions between said flanges and said passage.

In witness-whereof I have signed my name hereto this 30th day ofwAugust 1920;

J OHN A. DICKERMAN. 

